Biometry Commons^™

Model For Calculating Impact Force For Individualized Hip Fracture Prediction During A Fall, Alisha Agarwal, Daniel Kargilis, Nishtha Gupta, Michael Chang, Rui Feng, Gregory Chang, Chamith S. Rajapakse

Student Papers, Posters & Projects

Osteoporotic-related weakening of bone is a common cause of hip fractures. The standard of care for the diagnosis and management of osteoporosis is the dual-energy x-ray absorptiometry bone mineral density T-scores. Many individuals considered nonosteoporotic, however, still sustain fractures since these tools do not incorporate vital bone parameters and subject-specific characteristics. The purpose of this work was to (1) develop a simple analytical model for estimating the force exerted on the femur during a fall (i.e., impact force) based on measurable patient metrics and (2) define a quantifiable fracture risk index by comparing finite-element-derived bone strength and impact force, which …

“Regression To The Mean”: The Confluence Of Eugenics And Statistics In The 19th And 20th Centuries, Emrys G. King

Pomona Senior Theses

The work of this thesis is twofold — first, qualitatively characterizing the confluence between the British eugenics and statistics movements in the late 19th and early 20th centuries, and second, quantitatively analyzing the effect of this foundation on pedagogical materials in the growing field of statistics between 1880 and 1970. Towards the first goal, the history of the method of least squares, state statistics, and positive and negative eugenics are outlined, followed by a close reading of the foundational texts authored by Francis Galton and Karl Pearson that introduced linear regression. Towards the latter goal, English-language statistics textbooks published between …

Disparities In The Prevalence Of Hospitalizations And In-Hospital Mortality Due To Acute Myocardial Infarction Among Patients With Non-Alcoholic Fatty Liver Disease: A Nationwide Retrospective Study, Umar Hayat, Faisal Kamal, Muhammad Kamal, Wasique Mirza, Tariq Ahmad, Manesh Gangwani, Dushyant Dahiya, Hassam Ali, Shiva Naidoo, Sara Humayun, Hayrettin Okut, Muhammad Aziz

Division of Gastroenterology and Hepatology Faculty Papers

Background: Non-alcoholic liver disease (NAFLD) may be associated with cardiovascular diseases; however, only a few studies have analyzed this relationship. We aimed to assess the epidemiologic data and the association between NAFLD and acute myocardial infarction (AMI) in the United States. Methods: The National Inpatient Sample (NIS) database 2016-2019 was queried using ICD10-CM diagnostic codes to identify hospitalizations of AMI + NAFLD. Essential demographic variables were analyzed to determine the disparities in the prevalence of AMI hospitalizations and deaths among NAFLD patients. Univariate and multivariate logistic regression models determined the association between NAFLD and AMI hospitalizations and death. …

Effects Of Sars-Cov-2 Variants On Cd8+ T Cell Epitope Diversity: Estimating Clinical Severity In The United States, Grace Kim, Jacob Elnaggar, Maya Sevalia, Najah Nicholas, Mallory Varnado, Judy Crabtree, Lucio Miele

School of Medicine Faculty Publications

Association for Clinical and Translational Science 2024; April 3 - April 5, 2024; Las Vegas, NV

Population Health Management, Data And Technology, Helena Ladd, Cody Hepp, Anna Mccloud, Hannah Granger, Mary Ellen Hethcox, Samuel Calabrese

Pharmacy and Wellness Review

No abstract provided.

A Statistical Method For The Conservative Adjustment Of False Discovery Rate (Q-Value), Yinglei Lai

Epidemiology Faculty Publications

Background

q-value is a widely used statistical method for estimating false discovery rate (FDR), which is a conventional significance measure in the analysis of genome-wide expression data. q-value is a random variable and it may underestimate FDR in practice. An underestimated FDR can lead to unexpected false discoveries in the follow-up validation experiments. This issue has not been well addressed in literature, especially in the situation when the permutation procedure is necessary for p-value calculation.

Results

We proposed a statistical method for the conservative adjustment of q-value. In practice, it is usually necessary to calculate p …

Hpcnmf: A High-Performance Toolbox For Non-Negative Matrix Factorization, Karthik Devarajan, Guoli Wang

COBRA Preprint Series

Non-negative matrix factorization (NMF) is a widely used machine learning algorithm for dimension reduction of large-scale data. It has found successful applications in a variety of fields such as computational biology, neuroscience, natural language processing, information retrieval, image processing and speech recognition. In bioinformatics, for example, it has been used to extract patterns and profiles from genomic and text-mining data as well as in protein sequence and structure analysis. While the scientific performance of NMF is very promising in dealing with high dimensional data sets and complex data structures, its computational cost is high and sometimes could be critical for …

Models For Hsv Shedding Must Account For Two Levels Of Overdispersion, Amalia Magaret

UW Biostatistics Working Paper Series

We have frequently implemented crossover studies to evaluate new therapeutic interventions for genital herpes simplex virus infection. The outcome measured to assess the efficacy of interventions on herpes disease severity is the viral shedding rate, defined as the frequency of detection of HSV on the genital skin and mucosa. We performed a simulation study to ascertain whether our standard model, which we have used previously, was appropriately considering all the necessary features of the shedding data to provide correct inference. We simulated shedding data under our standard, validated assumptions and assessed the ability of 5 different models to reproduce the …

Meta-Analysis Of Gene Expression Studies, Umaporn Siangphoe

Theses and Dissertations

Combining effect sizes from individual studies using random-effects models are commonly applied in high-dimensional gene expression data. However, unknown study heterogeneity can arise from inconsistency of sample qualities and experimental conditions. High heterogeneity of effect sizes can reduce statistical power of the models. We proposed two new methods for random effects estimation and measurements for model variation and strength of the study heterogeneity. We then developed a statistical technique to test for significance of random effects and identify heterogeneous genes. We also proposed another meta-analytic approach that incorporates informative weights in the random effects meta-analysis models. We compared the proposed …

Approximating Confidence Intervals About Discrete Time Survival/Cumulative Incidence Estimates Using The Delta Method, Alexis Dinno, Jong-Sung Kim

Community Health Faculty Publications and Presentations

Poster focuses on answering the questions whether and when and event will happen in a population at risk.

The Relationship Between The Level Of Support Group Participation And Psychosocial Factors In Prostate Cancer Patients Treated With Proton Therapy, Carol A. L. Davis

Loma Linda University Electronic Theses, Dissertations & Projects

Background. The role of support groups for cancer patients is known to be beneficial in helping people adjust to the disease, and cope with the myriad of effects that cancer has on quality of life. Although many people express interest in attending such support groups, few attend regularly. It is unclear what characteristics distinguish those who use such services from those who do not, especially among proton therapy patients.

Objective. To examine demographic and psychosocial characteristics associated with the Brotherhood of the Balloon (BOB) prostate cancer support group membership, a unique treatment-focused group originating at Loma Linda University Medical Center …

A Bayesian Approach To Dose-Response Assessment And Drug-Drug Interaction Analysis: Application To In Vitro Studies, Violeta G. Hennessey

Dissertations and Theses (Open Access)

The considerable search for synergistic agents in cancer research is motivated by the therapeutic benefits achieved by combining anti-cancer agents. Synergistic agents make it possible to reduce dosage while maintaining or enhancing a desired effect. Other favorable outcomes of synergistic agents include reduction in toxicity and minimizing or delaying drug resistance. Dose-response assessment and drug-drug interaction analysis play an important part in the drug discovery process, however analysis are often poorly done. This dissertation is an effort to notably improve dose-response assessment and drug-drug interaction analysis.

The most commonly used method in published analysis is the Median-Effect Principle/Combination Index method …

Understanding The Physical Properties That Control Protein Crystallization By Analysis Of Largescale Experimental Data, W. Nicholson Price Ii, Yang Chen, Samuel K. Handelman, Helen Neely, Philip Manor, Richard Karlin, Rajesh Nair, Jinfeng Liu, Michael Baran, John Everett, Saichiu N. Tong, Farhad Forouhar, Swarup S. Swaminathan, Thomas Acton, Rong Xiao, Joseph R. Luft, Angela Lauricella, George T. Detitta, Burkhard Rost, Gaetano T. Montelione, John T. Hunt

Law Faculty Scholarship

Crystallization is the most serious bottleneck in high-throughput protein-structure determination by diffraction methods. We have used data mining of the large-scale experimental results of the Northeast Structural Genomics Consortium and experimental folding studies to characterize the biophysical properties that control protein crystallization. This analysis leads to the conclusion that crystallization propensity depends primarily on the prevalence of well-ordered surface epitopes capable of mediating interprotein interactions and is not strongly influenced by overall thermodynamic stability. We identify specific sequence features that correlate with crystallization propensity and that can be used to estimate the crystallization probability of a given construct. Analyses of …

Immediate Implant Placement In Extraction Sites With Periapical Lesions: A Retrospective Study, Yuan-Lung Hung

Loma Linda University Electronic Theses, Dissertations & Projects

Immediate implant placement into fresh extraction sites has become a relatively routine clinical procedure with a favorable prognosis. However, immediate placement into extraction sockets with lesions has not been extensively documented in humans. Therefore, the purpose of this study was to retrospectively determine the survival rate of implants placed into extraction sockets with visible periapical lesions.

Patient charts of 544 immediately placed implants from Loma Linda University School of Dentistry, Center for Prosthodontics and Implant Dentistry were examined. Eighty-six of the 544 implants had been placed immediately into extraction sockets with periapical lesions and they were included in this study. …

Facial Typing Methods : A Comparative Study, James A. Grabow

Loma Linda University Electronic Theses, Dissertations & Projects

Facial typing methods are used to determine to which of three basic facial pattern categories an individual patient belongs. These three categories are mesofacial, brachyfacial, and dolichofacial. It is important to establish the correct facial type because the reaction to treatment mechanics and the stability of the denture is dependent upon the analysis of the facial patterns. The purpose of this paper was to show a comparative study of facial typing classification methods used on 100 patients (47 boys and 53 girls). The eight different methods used were as follows: Bioprogressive, Ricketts LLU1, LLU2, QuickCeph™, Jarabak, Facial-Mandibular Index, and Steiner. …

The Incidence And Magnitude Of Tooth-Size Discrepancies In Caucasians, Blacks And Hispanics, Dana R. Shaltry

Loma Linda University Electronic Theses, Dissertations & Projects

The present investigation utilized the Bolton Analysis to determine the incidence and magnitude of tooth-size discrepancy in a sample of 227 orthodontic patients. Sliding calipers were used to measure the mesiodistal width of the permanent dentition on pretreatment study models of 120 Caucasian, 51 Black, and 56 Hispanic patients. The overall and anterior ratios were analyzed and the frequency and magnitude of excess maxillary and mandibular tooth structure was determined. Each racial group demonstrated a significant incidence of tooth-size discrepancy in the maxillary and mandibular arches of a magnitude (> 0.5mm) which would require some form of correction. In addition, …

Xeroradiography & Conventional Radiography : Comparative Imaging Of The Temporomandibular Joint, Nelson R. Gatov

Loma Linda University Electronic Theses, Dissertations & Projects

An investigation was conducted to evaluate the application of Xeroradiography for imaging the Temporomandibular Joint using the Updegrave and Weinberg positioning boards and to compare these images to those obtained by conventional radiography using the same positioning boards.

A cadaver head in which three spherical radiopaque implants had been placed was used in this study. A General Electric Model 1000 (Dental Unit) was the source of radiation. The conventional radiographs were produced on Dupont Cronex 2DC film and processed by a Phillips 810 automatic processed by a Xerox "125 System".

MAGNIFICATION

A comparison of the implant sphere diameters and the …

Selected Physiological Responses To A Back Rub, Norma (Ewing) Anderson

Loma Linda University Electronic Theses, Dissertations & Projects

The back rub, which has been an established part of evening patient care for many years, is given to promote relaxation and sleep as well as to promote skin care. Yet its place in modern nursing seems questionable. Today's nurse is less willing to practice using empirically established procedures.

There have been few investigations showing the effect of massage to the back and no studies have shown that a brief back rub, as given by nurses, promotes relaxation. In cardiovascular nursing there is some controversy as to whether or not the back rub causes stimulation to the cardiovascular system that …

Sex Determination By Cephalometry And Odontometry, Clair R. Hopkins Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

Plaster casts of teeth and lateral cephalometric roentgenograms were studied to see with what degree of accuracy sex could be determined. The sample considered was made up of one hundred and forth-four individuals--50 males and 94 females--being treated in the Graduate Orthodontic Department of the Loma Linda University School of Dentistry. The age range for the boys was from 15 to 19 and for the girls, from 14 to 20. Data was obtained for the following variables from tracings of the roentgenograms and from the dental casts:

1. Glabello-occipital length
2. Articulate to nasion
3. The gonial angle of the mandible
4. Prosthion to …