26419 research outputs found
Sort by
Two Essays on Firms’ Reactions to Major Events in Rival Companies
No full textThe first essay of this dissertation examines the influence of peer credit rating downgrades on firms’ financial decisions. The results show that firms respond to a rival’s downgrade by increasing excess debt capacity, excess cash holdings, excess net working capital, and the excess cash conversion cycle. They also accelerate their speed of adjustment (SOA) toward target capital structures. These adjustments are motivated by a desire to mitigate the higher costs and risks associated with financial distress and to preserve competitive advantage. Moreover, firms with more capable managers, and those operating in environments with greater market competition, higher information asymmetry, and higher internal uncertainty, adjust their financial policies more quickly toward target levels. The findings contribute new insights into the peer effects that shape corporate financial behavior.
The second essay, using a sample of 68,608 firm-year observations of firms that appointed a female CEO and their industry rivals, investigates how rival firms respond to such appointments. The results indicate that rival firms led by male CEOs—who may perceive themselves as more capable than the newly appointed female CEO and expect her to be less inclined toward risky decisions—increase their risk-taking after the appointment. This heightened risk-taking subsequently leads to a decline in performance, with overinvestment identified as the primary channel linking female CEO appointments to the performance drop in rival firms. In addition, the analysis identifies firm-specific, rival-specific, and industry-level factors that moderate the relationship between female CEO appointments and changes in rivals’ risk-taking and performance
Eccentric Hamstring Strength and ACL Injury Risk in NCAA Division I Female Field Hockey Athletes
No full textAnterior cruciate ligament (ACL) injuries remain a pervasive issue in female collegiate athletics, particularly in sports demanding frequent decelerations, cuts, and high-speed movements such as field hockey. Despite the high injury burden, limited research has investigated biomechanical and workload-based risk factors specific to NCAA Division I female field hockey athletes. This study aimed to evaluate the relationship between changes in eccentric hamstring strength and movement load metrics with changes in a composite ACL Risk Index. The sample included nine NCAA Division I female field hockey players who completed a 13-week offseason strength and conditioning program. Eccentric hamstring strength was measured using the NordBord Hamstring Testing System (Vald Performance, Newstead, Australia), while high-speed distance (HSD) and high-intensity decelerations (HID) were captured via Catapult Vector GPS units. Z-score transformations of HSD and HID changes were used to create an individualized ACL Risk Index. A standard multiple linear regression was performed to identify predictors of change in ACL Risk Index. Change in HID emerged as the only statistically significant predictor (β = .686, p = .028), underscoring the critical role of braking loads in modulating ACL injury risk. While changes in between-limb hamstring strength, defined as limb asymmetry (β = –.641, p = .117), and eccentric hamstring strength (β = .309, p = .383) did not reach statistical significance, both contributed to the overall variance explained by the regression model, indicating potential clinical relevance in predicting ACL risk changes. The overall model explained 83.8% of the variance in ACL Risk Index scores (R² = .838, p = .070), suggesting practical significance despite the small sample size. This study supports the integration of field-based strength assessments and wearable GPS technologies to identify modifiable risk factors in female athletes. Findings reinforce the importance of eccentric strength development and braking load management in ACL injury prevention strategies. Limitations included the small sample size, absence of inertial measurement data for cutting intensity, and reliance on secondary data collection. Future research should incorporate multi-site samples, longer-term injury tracking, and more granular biomechanical analysis to improve generalizability and predictive accuracy. Overall, this research contributes novel insights into sport-specific ACL risk profiling and strengthens the foundation for individualized injury mitigation strategies in strength and conditioning practice
Structural Insights into the Enterovirus Replication Platform: A Potential Target for Inhibiting Viral Replication
No full textViral replication is a complex and vital part of the picornavirus life cycle. A key structure in this process is the predicted cloverleaf located at the 5’ end of the positive-sense strand (5’CL) or at the 3’ end of the negative-sense strand (3’CL). To develop effective antiviral treatments against enteroviruses, it is crucial to better understand the role of the cloverleaf structure in viral replication. This dissertation aims to deepen the understanding of the conservation, structure, and dynamics of the enterovirus replication platform through three projects.
First, the conservation and divergence of 209 enterovirus 5’CL were analyzed using bioinformatic tools. By classifying the CLs into six distinct groups, regions of high conservation found in all studied 5’CLs included known protein interaction sites as well as regions with unknown functions. Therefore, this work offers a more detailed understanding of both sequence and structural conservation and divergence, which could be useful for developing a broad-spectrum antiviral.
Second, the conformational structure of the 5’CLs in solution was studied using various experimental techniques, including circular dichroism (CD), size exclusion chromatography (SEC), and small-angle X-ray scattering (SAXS). It was found that the behavior of the 5’CL in solution greatly depends on factors such as serotype, ionic conditions, and the tendency to dimerize. Therefore, this work highlights the importance of combining crystal and solution methods to better understand the CL structure.
Finally, the tertiary structure of the 3’CL of Coxsackievirus B3 (CVB3) is examined using experimental methods, such as NMR and SAXS, combined with computational methods. Investigating the template tertiary structure provided insights into the monomer structure of the CVB3 3’CL, as well as its tendency for dimerization. This work aims to establish a structural baseline for the 3’CL to gain insight into potential antiviral targets.
Overall, the work presented in this dissertation contributes valuable insights into the structural properties and conservation of the enterovirus cloverleaf, enhancing our understanding of the potential of the 5’CL or 3’CL as an antiviral target
Willingness to Use Long-Acting Injectable Pre-Exposure Prophylaxis (LAI-PrEP) Among Black Cisgender Women in the Southern United States
No full textBackground
Long-acting injectable pre-exposure prophylaxis (LAI-PrEP) for HIV prevention may improve adherence for those with concerns with daily pills. Limited data exist on LAI-PrEP acceptability among Black women in the U.S., a population vulnerable to HIV. We assessed willingness to use LAI-PrEP among Black women eligible for PrEP in the Southern U.S.
Methods
We conducted a cross-sectional online survey of HIV-negative Black women from March to June 2022 in the U.S. South. Participants provided information on sociodemographic characteristics, HIV knowledge, PrEP awareness, and use, stigma, risk perception, medical mistrust, and healthcare access. Multivariate logistic regression models determined factors associated with willingness to use LAI-PrEP.
Results
Of 491 women, the mean (SD) age was 40.1 (17.5), 53% of participants had a college degree or lower, 79% were single, and 80% resided in urban/suburban settings. Thirty-nine percent were aware of PrEP before the study and 36.7% of women were willing to use LAI-PrEP. In multivariate analyses, PrEP awareness [adjusted odds ratio (aOR=2.37, 95% CI 1.40, 3.73, p \u3c 0.001), having a personal clinician (aOR=2.01, 95% CI 1.10, 3.68, p = 0.02), HIV worried (aOR=1.78, 95% CI 1.09, 2.89, p = 0.02), and medical trust (aOR=1.41, 95% CI 1.03, 1.93, p = 0.04) were statistically associated with willingness to use LAI-PrEP. However, the healthcare stereotype (beliefs that healthcare is biased) had lower odds of using LAI-PrEP (aOR=0.94, 95% CI 0.89, 0.99, p = 0.04).
Conclusion
Black women at risk for HIV are more likely to consider injectable PrEP when they understand HIV risk factors, are aware of PrEP, have a clinician, and trust the medical care. Implementing client-centered care interventions could effectively address medical mistrust and enhance engagement in HIV prevention services among Black women
Comparing Immediate and Short-term Outcomes and Success in Conservative Versus Surgical Treatment of Pulmonary Embolism (PE)
No full textBACKGROUND:
Pulmonary embolism (PE) is a dangerous and life-threatening medical condition which significantly increases risk of cardiovascular fatality. Although each PE treatment strategy has shown to be effective to some degree, there is limited data on they compare. The objective of this study is to evaluate the outcomes of PE treatment with anticoagulation versus interventional treatments.
METHODS:
A Retrospective chart review was performed of all patients identified as having a PE at Sentara Norfolk General Hospital from January 1, 2021 to December 31, 2022. Using Redcap, patient information was recorded, including age, sex, race, body mass index, and pertinent history. Information about their condition and details of the pulmonary embolism were recorded, including vitals, labs, and heart function obtained from echocardiograms. The intervention type was recorded, with details of any procedures as well as the in hospital or 30-day mortality.
RESULTS:
These are the preliminary results for comparing outcomes of pulmonary embolism treatment options. 366 patients were analyzed, with 197 female and 169 males having an average age of 65.5 years. The most common treatment was anticoagulation therapy only (60.2%), followed by mechanical thrombectomy (12.8%), systemic tPA (11.4%), CDT with EKOS (11.2%), and CDT with tPA (4.1%). 45 patients suffered an in-hospital death or mortality within 30 days of treatment (12.3%)
CONCLUSIONS:
The majority of patients who had an unsuccessful outcome were treated with anticoagulation therapy only. However, the treatment with the lowest success rate was systemic tPA
Novel Percutaneous Repair of Femoral Pseudoaneurysms Using Perclose Proglide™: A Case Series
No full textBACKGROUND - This case series details the novel use of the Perclose ProGlide closure device to successfully repair three separate cases of iatrogenic femoral pseudoaneurysms (PSAs) without attempting other modalities first. Conventional treatment methods of ultrasound-guided compression, duplex-directed thrombin injection (DDTI), or open surgical repair were contraindicated in these patients due to unique anatomy or advanced comorbidities.
METHODS – Details were gathered via a retrospective chart review.
RESULTS - In the first case, a 73-year-old female had an access site PSA off the superficial femoral artery (SFA) with concomitant arteriovenous fistula (AVF) and advanced cardiac disease. The ProGlide device was deployed through the PSA neck with successful hemostasis. In the second case, a 78-year-old male had an asymptomatic access site PSA with a short and wide neck, as well as an endoleak following physician modified TEVAR. Access to repair the endoleak was obtained through the PSA neck. The ProGlide was successfully deployed following endoleak repair. In the third case, a 70-year-old female with chronic osteomyelitis of the left foot developed a left femoral PSA with a short and wide neck following bilateral lower extremity vascular interventions. The ProGlide was successfully deployed through the PSA neck, and the patient recovered well. All three patients maintained distal flow after ProGlide deployment.
CONCLUSIONS - Further evaluation of the efficacy of the ProGlide device as a treatment modality for PSAs is required. This case series provides preliminary evidence supporting its potential as a modality to address iatrogenic femoral pseudoaneurysms
Remica Bingham-Risher
No full textPublicity photo submitted by author/presenter for ODU\u27s Annual Literary Festival 2024.
Photo by Jennifer Natalie Fishhttps://digitalcommons.odu.edu/litfest_images/1000/thumbnail.jp
A Comprehensive Review of Piezoelectric PVDF Polymer Fabrications and Characteristics
No full textPolyvinylidene fluoride (PVDF) polymer films, renowned for their exceptional piezoelectric, pyroelectric, and ferroelectric properties, offer a versatile platform for the development of cutting-edge micro-scale functional devices, enabling innovative applications ranging from energy harvesting and sensing to medical diagnostics and actuation. This paper presents an in-depth review of the material properties, fabrication methodologies, and characterization of PVDF films. Initially, a comprehensive description of the physical, mechanical, chemical, thermal, electrical, and electromechanical properties is provided. The unique combination of piezoelectric, pyroelectric, and ferroelectric properties, coupled with its excellent chemical resistance and mechanical strength, makes PVDF a highly valuable material for a wide range of applications. Subsequently, the fabrication techniques, phase transitions and their achievement methods, and copolymerization and composites employed to improve and optimize the PVDF properties were elaborated. Enhancing the phase transition in PVDF films, especially promoting the high-performance β-phase, can be achieved through various processing techniques, leading to significantly enhanced piezoelectric and pyroelectric properties, which are essential for diverse applications. This concludes the discussion of PVDF material characterization and its associated techniques for thermal, crystal structure, mechanical, electrical, ferroelectric, piezoelectric, electromechanical, and pyroelectric properties, which provide crucial insights into the material properties of PVDF films, directly impacting their performance in applications. By understanding these aspects, researchers and engineers can gain valuable insights into optimizing PVDF-based devices for various applications, including energy-harvesting, sensing, and biomedical devices, thereby driving advancements in these fields
International Causes of Hunger and Malnutrition: Food Insecurity and the Global Economy
No full textThis book examines the international causes of hunger and malnutrition and reveals how critical elements of the global economy heighten food insecurity in the developing world.
At present, over two billion people in the developing world do not have secure access to safe, sufficient, and nutritious food. With the global population projected to rise to almost 10 billion by 2050, ensuring universal access to food will become increasingly urgent. The global community will need to redouble its efforts to effectively address the underlying causes of food insecurity. Within countries, a number of causes – poverty, poor governance, civil conflict, environmental decline - are immediately apparent and must be addressed to have any hope of lessening hunger and malnutrition. At the same time, a number of other factors well beyond national borders often constitute equal or greater obstacles to meeting the nutritional needs of all people. These factors are not nearly as visible and are largely outside the control of individual countries and local communities. This book examines how core elements of the global economy cause, prolong, and intensify food insecurity in the developing world. Emphasis is placed on agricultural trade, seed privatization, transnational land acquisitions, industrial fishing, and climate change. Understanding how these five factors impact the poorest communities in the poorest countries is essential for constructing an equitable, inclusive, and sustainable global food system that meets the nutritional needs of all people. By highlighting five major international causes of hunger and malnutrition, this book offers an alternate framework for understanding and combatting global food insecurity.
This book will be of particular interest to students, scholars, and practitioners in the fields of global food security, international development, and global political economy. [From the publisher]https://digitalcommons.odu.edu/politicalscience_geography_books/1047/thumbnail.jp
\u3ci\u3eSchistosoma mansoni\u3c/i\u3e Infection Causes Consistent Changes to the Fecal Bacterial Microbiota of Mice Across and Within Sites
No full textEggs of Schistosoma mansoni are produced by adult female worms in mesenteries of infected hosts. Eggs can cross the intestinal barrier and form granulomas in the tissue or breach and exit the host through fecal excretion. These interactions may affect the host microbiome assemblages. Given the potential for schistosomal alteration of host gut microbiome and subsequent effects on the fecal bacterial composition, it is important to conduct controlled microbiome studies on model animals. While pursuing these studies, it is important to take into account the different conditions in which microbiome studies are conducted and their consequent impacts on variability and reproducibility of results. In particular, we are interested in inter-institutional effects on controlled microbiome studies, in which the study location itself may impact study outcomes. In this work, we report global changes caused by acute and chronic schistosomiasis on the fecal microbiome of mice at two different institutions and three timepoints