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Integrated Approaches For Assessing Four-Leg Signalized Intersection Safety: Statistical Modeling And Machine Learning Techniques
No full textIntersections are the most crash-prone areas, accounting for a significant portion of all traffic crashes, making their safety a critical concern. Existing studies and guidelines, such as the Highway Safety Manual (HSM), provide safety performance functions (SPFs) and intersection influence area (IIA) based on data from a limited number of states, insufficient traffic crash variables, and traditional statistical methods. Though previous studies have provided valuable insights into intersection safety, they often lack a comprehensive approach that parallelly evaluates parametric and nonparametric methods to examine crash severity, seasonality, and collision types. This need is particularly evident in regions like North Dakota (ND), where distinct spatial and temporal characteristics reveal the shortcomings of generalized national guidelines. This study aims to develop local IIA from crash data distribution and SPF models to address the variability in crash characteristics at four-leg signalized intersections (FLSGI) in ND. It employs a logistic regression technique to identify IIAs based on accuracy, precision, and Absolute False Frequency Difference (AFFD) metrics. The results showed that locally calibrated IIAs achieved the lowest AFFD, strongly aligning with regional crash data. The findings indicate that IIAs were longer under adverse road and low-speed limit conditions and ranged from 82 ft to 335 ft. Additionally, SPFs were developed for total crashes and various crash categories, including property damage only (PDO) crashes, killed, injured, or incapacitated (KABC) crashes, seasonal crashes (dry and wet season crashes), and crashes by different collision types (rear end, angle, and sideswipe crashes). The SPFs were developed using fixed and random effect parametric models, such as Poisson Regression (PR), Negative Binomial (NB), Zero-Inflated Poisson (ZIP), Zero-Inflated Negative Binomial (ZINB), and nonparametric techniques like Random Forest (RF) and Extreme Gradient Boosting (XGBoost). The effect of key factors such as truck volume and intersection geometry were incorporated into the models. The performance of these models was assessed using AIC, BIC, log-likelihood (LL), and Mean Squared Error (MSE). It was found that the SPFs derived from the Random Effects Negative Binomial (RENB) and Random Effects Zero-Inflated Negative Binomial (REZINB) approaches are the best fit, simple, and practical models of all the parametric models. A transferability analysis of the best models for the East and West regions of the state revealed that local models have a lower Transferability Index (TI), and these models developed for each region yield a simplified and better-fit model. Moreover, the results demonstrate that ML approaches produced the lowest MSE and have superior predictive accuracy. Though both RF and XGBoost models capture non-linear relationships between variables, the k-fold cross-validation result revealed that XGBoost exhibited superior predictive accuracy for most SPFs, enhanced through hyperparameter tuning. Furthermore, feature importance and sensitivity analysis reveal that Average Annual Daily Traffic (AADT, log-transformed), lane widths, and turn lanes are variables that significantly affect the outcome of each SPF model. Finally, a comparative analysis of SPFs from locally developed IIAs and HSM thresholds demonstrated that the local IIA SPFs showed a better model fit and accuracy. Overall, the RF and XGBoost techniques are superior due to their better performance and accuracy, while the RENB and REZINB models offer greater interpretability and are less complex, making them more practical for practitioners. In conclusion, this study emphasizes the benefits of locally calibrated models for improving crash prediction and informing policy development. It provides a robust framework for researchers, evaluating both parametric and nonparametric methods to analyze crash data with respect to location, severity, seasonality, and collision types, thereby encouraging further exploration of intersection safety dynamics at a local level. By adopting these context-specific and data-driven strategies, transportation planners can better inform policy decisions and implement targeted measures to reduce crashes and improve safety
Applied Indigenous Knowledge Translation: Naatookyookaasii
Get PDFThis dissertation portfolio comprises three projects aimed at advancing Indigenous health and integrating cultural perspectives into research and practice. Guided by principles of community engagement and ethical research practices, these projects align closely with my career goals in Indigenous health policy and research. The first project, Measuring Wellness Through Indigenous Partnerships, is a scoping review that examines global Indigenous wellness measures and assesses community involvement in defining measures of wellness. This review informs future practice directions and supports my advocacy for culturally responsive methodology. The second project, Reciprocal Facilitation: Protocols and Practices for Listening Sessions with Tribal Communities, introduces a facilitation manual designed to foster inclusive dialogue and honor Indigenous knowledge systems. This initiative promotes community-based research practices that respect diverse perspectives. The third project, Evaluation Report: Virtual Indigenous Data Science Academy 2022, evaluates a data science curriculum from an Indigenous perspective. This endeavor examined a data science curriculum based on integration of cultural priorities into the academy, how the program addressed community needs and enhanced educational outcomes. Each project reflects my commitment to ethical research conduct and cultural sensitivity in collaborating with Indigenous communities. These efforts contribute significantly to advancing Indigenous health knowledge and fostering sustainable research practices that support community-defined goals and aspirations
The Effects of Blood Flow Restriction on Electromyography Activity of Proximal and Distal Upper Extremity Musculature
Get PDFPurpose/Hypothesis: Blood flow restriction therapy (BFR) has become a popular strength training and intervention method. Research shows BFR increases muscular hypertrophy and strength, mostly attributed to vascular occlusion. The purpose of this study is to examine BFR effects on proximal and distal muscle electromyography (EMG) activity to evaluate characteristics of fatigue in the infraspinatus (INFRA) and extensor carpi radialis brevis (ECRB) during resistive side-lying shoulder external rotation (ER). Number of Subjects: 51
Materials/Methods: Fifty-one college students, 31 females, and 20 males participated in the study. Shoulder ER peak force was identified in side-lying utilizing a MicroFET. Participants completed shoulder ER at 20% of the recorded peak force. Surface EMG electrodes were placed on the INFRA and ECRB muscles. Participants completed 2 trials of shoulder ER in side-lying with and without BFR with a 30-minute rest period between trials. A trial ended upon volitional fatigue or when 2 incorrect repetitions were observed. EMG data were collected and analyzed using Noraxon MyoResearch software. A repeated measures pairwise comparison analysis was performed on the EMG frequency slope, mean frequency, and mean amplitude using SPSS.
Results: Significant differences (p \u3c .001) were noted in average repetitions with BFR (34.5 reps) and without BFR (44.6 reps). The slope of the EMG frequency was negative for muscles in both conditions with statistical significance (p
Conclusion:This study demonstrated increased shoulder ER repetitions without BFR compared to utilizing BFR. The INFRA and ECRB muscles demonstrated similar EMG amplitude changes; however, the frequency was more negative with BFR along the ECRB. The slope of frequency was significant (p
Clinical Relevance: Research identifies the benefits of various BFR protocols on distal musculature; however, there is limited research for muscles proximal to the occlusion cuff. Determining the effects various BFR application protocols may have on proximal musculature could assist in rehabilitation programming that optimizes BFR effects in the treatment of UE pathologies
Treatment of Plantar Fasciitis for an Individual with an Intellectual Disability that Interferes with Communication and Compliance to Home Program: A Case Report
Get PDFIntroduction. Approximately 10% of Americans deal with plantar fasciitis. Plantar fasciitis can lead to negative impacts on quality of life. Furthermore, treatment of individuals with intellectual disabilities affecting communication presents a unique set of difficulties. This case study summarizes the evaluation process and treatment of one female patient with bilateral plantar fasciitis who also has an intellectual disability.
Case Description. This specific patient was diagnosed with intellectual disability secondary to a carbamoyl phosphate synthetase I (CPS) deficiency at birth. She presented to physical therapy at age 35 with bilateral plantar heel pain of 6 months following an increase in activity levels.
Intervention. Treatment consisted of 2 sessions per week of 45 minutes each for 4 weeks, followed by 1 session per week for 6 weeks. Interventions consisted of passive/active gastrocnemius and plantar fascia stretching, Instrument Assisted Soft Tissue Mobilization (IASTM), static cryotherapy, self-tennis ball plantar fascia massage, hip joint mobilizations, and gastrocnemius strengthening.
Outcomes. Prior to discharge, the patient demonstrated improvements in activity tolerance measured by duration of treadmill ambulation, range of motion, reported pain measured by the visual analog pain scale, and participation in activities.
Discussion. Throughout the duration of this case study, it was found that the patient responded well to passive treatments early into the treatment series such as passive stretching, IASTM, and cryotherapy. Communicating pain was a major barrier to treatment. This was overcome by using the visual analog pain scale to quantify pain intensity. Duration of treadmill walking was useful to assess activity tolerance and track progress. Range of motion slowly improved over the 10 weeks; supporting the use of passive and active stretching. This case study supports the literature on plantar fascia by supporting the use of increasing range of motion and slowly increasing activity levels. It adds to the current literature by providing more information on how to alter treatment and use of objective measures for individuals with intellectual disabilities as this is an area where the literature is lacking. Further research would be useful for the evaluation and treatment of individuals with intellectual disabilities who are dealing with overuse injuries
Porcelain Soup Spoon
No full textThis item is not included in the original collection inventory. The item is a porcelain soup spoon with a floral design and blue background. There is also a manufacturer stamp on the bottom of the spoon.https://commons.und.edu/fritzcollection/1227/thumbnail.jp
Development, Characterization, And Application Of Nanomaterials For Target Detection And Therapeutic Study
No full textNanomaterials have emerged as a pivotal area of research in chemistry, driven by their unique properties that make them suitable for both industrial and biomedical applications. Among nanomaterials, nanozyme is a series of nanomaterials with enzyme-mimetic activities that can proceed with the catalytic reactions of natural enzymes, conferring significant potential for their use in various biomedical applications. Herein, we describe three types of nanomaterials products with distinct properties and applications: 1) Fe³⁺-doped graphene quantum dots (GQDs) for sensitive H₂O₂ detection; 2) ratiometric fluorescent nanoprobes based on near-infrared (NIR) semiconducting polymer dots for label-free detection of dopamine; and 3) Multifunctional near Infrared polymer pots for enhanced synergistic photodynamic/photothermal therapy.In this dissertation, the first chapter is a comprehensive review of nanozymes and their biotargets, including the challenges with natural enzymes and the rapid development of nanozymes, their synthetic counterparts. This chapter highlights the different types of nanozymes and their functional groups, including metal or metal oxide-based nanozymes, metal-organic frameworks (MOFs), and carbon-based nanomaterials. I further explore and compare the reaction mechanisms of nanozymes, such as peroxidase, oxidase, and superoxide dismutase-like activities. I also provide my perspective on current and future applications for biosensing from ions, small molecules, nucleic acids, and proteins to cancer cell detection. The chapter was finished with current challenges in the field, suggesting future research directions to address impediments to nanozyme synthesis and application.
The second chapter details the development of sensitive fluorescence-based GQDs, synthesized using polyethyleneimine (PEI) as a precursor, doped with Fe³⁺ via a “bottom-up” method. The Fe³⁺ in the GQDs facilitated catalase-like activity by catalyzing H₂O₂ through a complex Fenton reaction. The synthesized GQDs-Fe exhibited a high quantum yield (67%) and rapid sensitivity to H₂O₂ in neutral pH, with a low limit of detection (LOD) of 20 nM, achieved within seconds. These features are a marked improvement compared with current methods.In the third chapter, ratiometric fluorescent nanoprobes based on NIR semiconducting Pdots were prepared by blending two semiconducting polymers: poly[(9,9-dioctyl-2,7-divinylenefluorenylene)-alt-(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene)] (PFPV) and Poly [2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl(9,9-dioctyl-9H-9-silafluorene-2,7-diyl)-2,5-thiophenediyl] (PSiF-DBT), combined with an amphiphilic polymer Poly(Styrene-Co-maleic anhydride) cumene terminated (PSMA). The strong NIR fluorescence exhibited was due to the efficient Förster resonance energy transfer (FRET) from PFPV to PSiF-DBT. Dopamine quenched the NIR fluorescence through photo-induced electron transfer (PET) process with an LOD of 70 nM when 1 mg/L of Pdots reacted with dopamine for 20 minutes in HEPES buffer (pH = 8) with specificity compared to other common cellular molecules and neutransmitters. The fourth chapter describes the synthesis of multifunctional NIR Pdots using poly (styrene-co-maleic anhydride) (PSMA) as a crosslinker and backbone to form a compact core. Poly [2,6-(4,4-bis (2-ethylhexyl)-4H-cyclopenta [2,1-b;3,4-b′] dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) was employed as both an NIR photosensitizer and thermal agent, while Mn²⁺ ions were incorporated to produce O₂ through H₂O₂ catalysis, thereby achieving a photothermal conversion efficiency of 53%, a singlet oxygen (¹O₂) quantum yield of 46%, and enhanced ¹O₂ quantum yield up to 64 % with 10 µM H₂O₂. The synergistic photodynamic and photothermal therapeutic effects were tested in MCF7 human adenocarcinoma cells, with results assessed via cell viability assays and confocal imaging under laser irradiation achieving a combination index of 0.25 at effective does (ED) 50, while Pdots showed non-cytotoxic properties without laser irradiation. The fifth chapter summarizes the three research projects, detailing the limitations of nanozymes for biosensing, ratiometric fluorescence nanoprobes for biosensing, and Pdots for cancer therapy. Future strategies to enhance the performance of these nanomaterials are discussed, including improving biocompatibility, targeting specificity, overcoming biological barriers, developing multifunctional nanomaterials, and ensuring sustainable design. Addressing these challenges is essential to solidifying the role of nanomaterials in advancing medical diagnostics and treatment. This dissertation will demonstrate the efficacy of nanoparticles as nanozymes in sensitive detection of H₂O₂ and dopamine, as well as their potential to enhance clinical applications of photodynamic/photothermal therapy for cancer treatment. The anticipated outcomes include the successful development of highly sensitive, fluorescent and specific nanoprobes for biomedical applications, and the establishment of multifunctional Pdots as potential agents in cancer therapy. These findings could significantly contribute to clinical interventions, making early disease diagnosis more accurate and improving the efficacy of late-stage cancer treatments
State Mill and Elevator, Grand Forks, N.D.
No full textUndated, color postcard of the North Dakota State Mill in Grand Forks. State Mill and Elevator, Grand Forks, N.D. and Capacity Mill 3,000 Barrels Flour Daily, Capacity Elevator 3,000,000 Bushels are printed on the front.https://commons.und.edu/gf-city-photos/1152/thumbnail.jp
Infographic: Equity Opportunities: Income: need for dental care among third grade students in North Dakota
Get PDFWe have third grade students in North Dakota whose dental care needs are not being met. Programs, providers, and initiatives need to focus on providing equal access to preventive dental care supplies and educational resources to support good dental hygiene. Children attending schools where more than 50% of the students are eligible for the national school lunch program (NSLP) have a significantly higher need for early or urgent dental care and a higher rate of rampant decay compared to those attending schools with less than 50% of students eligible for the NSL
Treating Rheumatoid Arthritis: Immunosuppression Versus Stem Cell Therapy
Get PDFThis literature review will discuss the difference in efficacy and side effect profile between methotrexate monotherapy and mesenchymal stem cell therapy for the treatment of rheumatoid arthritis. Rheumatoid arthritis is a debilitating inflammatory condition that effects a person’s mobility and can cause chronic, intense pain. Due to the side effect profile of methotrexate, mesenchymal stem cell therapy is being investigated as a treatment option. There were 11 scholarly articles evaluated for the purpose of this literature review. Data compiled from these studies supports the use of Mesenchymal stem cells as treatment for rheumatoid arthritis due to immunomodulatory effect on multiple immune components that contribute to the development of rheumatoid arthritis. Mesenchymal stem cell treatment was also less likely to cause serious side effects than methotrexate therapy. However, the determination of whether mesenchymal stem cell therapy is definitively more effective than methotrexate monotherapy cannot be made. This is due to a lack of robust research available for the evaluation of mesenchymal stem cell therapy on rheumatoid arthritis. Additionally, the exact mechanism by which mesenchymal stem cells provide the desired immunomodulatory effects is not yet well understood.https://commons.und.edu/pas-grad-posters/1302/thumbnail.jp