Multivariate ordered discrete response models

We introduce multivariate ordered discrete response models with general rectangular structures. From the perspective of behavioral economics, these non-lattice models correspond to broad bracketing in decision making, whereas lattice models, which researchers typically estimate in practice, correspond to narrow bracketing. In these models, we specify latent processes as a sum of an index of covariates and an unobserved error, with unobservables for different latent processes potentially correlated. We provide conditions that are sufficient for identification under the independence of errors and covariates and outline an estimation approach. We present simulations and empirical examples, with a particular focus on probit specifications

Essays in household finance and innovation

This thesis consists of two essays on household finance and one essay on innovation. Chapter 1 examines descriptively how UK credit card lenders set credit limits and interest rates for customers. First, I summarize the literature on credit card regulation and lenders’ choices of credit limits and interest rates. Second, I detail the relevant credit card regulation, focusing on how UK credit card lenders are required to advertize a “representative” interest rate for every credit card product they offer. Third, I describe my credit card dataset together with basic summary statistics. Finally, I offer a set of descriptive findings. My main results describe the limited variation in interest rates within credit card products relative to substantial variation in credit limits. In Chapter 2, I build on Chapter 1 by presenting and estimating an economic model of the UK credit card market. The modeling novelty is the link between individuals’ credit limits and lenders’ predictions of customers’ risk. With the estimated model, I examine a counterfactual scenario in which credit card lenders are subject to no costs and constraints in individualizing interest rates and credit limits, which the existing environment precludes. In this case, credit card lenders’ profits increase, consistent with lenders facing costs and constraints that discourage them from individualizing interest rates. In Chapter 3, we develop a dynamic structural model of patent screening incorporating incentives, intrinsic motivation, and multi-round negotiation. We use detailed data on examiner decisions and employ natural language processing to create a new measure of patent distance that enables us to study strategic decisions by applicants and examiners. We find that patent screening is moderately effective, given the existing standards for patentability. Examiners exhibit substantial intrinsic motivation that significantly improves the effectiveness of screening. A reform that limits negotiation rounds strongly increases screening quality. We quantify the annual net social costs of patent screening at $25.5bn, equivalent to 6.5% of U.S. private sector R&D

Evaluating Interprofessional Fast Forward Rounds for Transition of Care Education

Background: Interprofessional Education is gaining recognition by key pharmacy organizations for its value in healthcare education, producing various models for implementation among healthcare students and professionals. Unfolding cases incorporating transitions of care may improve student skills and attitudes toward interprofessional collaboration. Objectives: This project assessed the efficacy of unfolding cases in improving interprofessional skills and attitudes among pharmacy, nursing, and social work students. The ultimate goal is to integrate this model, if proven effective, into the curricula of multiple health science centers. Methodology: First, pharmacy, nursing, and social work students completed a pre-intervention survey regarding interprofessional skills and attitudes before discussing the first “fast-forward rounds” case in professional silos. After a transitions of care lecture, subjects completed the alternative cases in interprofessional groups in a crossover design. The comparable transitions of care cases included common healthcare topics that were challenging but within the scope of regular practice. “Fast forwards” between transitions of care required students to interpret changes in the case throughout the hospital stay. Following the interprofessional session, group debriefing allowed for feedback on cases, transitions, and differences working with and without other professions. Finally, a post-intervention survey was administered to measure changes in interprofessional attitudes and skills. Analysis: Kruskall-Wallis analysis identified differences among the three majors on the pretest and posttest separately. The Wilcoxon sign rank test assessed changes within each group since normal distribution was not assumed. A Chi-squared test analyzed demographic data. Results: Data analysis of results from the conference revealed a significant improvement in 15 of 25 survey questions in the composite group, while 14, 7, and 4 questions showed significant improvement in the pharmacy, nursing, and social work sub-analyses, respectively. Fewer questions showed significant improvement in the social work group, possibly due to the specific medical details of the cases as well as fewer social work participants relative to pharmacy and nursing. Discussion: Results suggest that this intervention can effectively improve student attitudes toward interprofessional collaboration and understanding of transitions of care. Changes can be made to improve the benefit to social work students and to increase the number of majors participating

Defining optimal soybean seeding rates and associated risk across North America

Soybean [Glycine max (L.) Merr.] seeding rate research across North America is typically conducted in small geo-political regions where environmental effects on the seeding rate × yield relationship are minimized. Data from 211 individual field studies (∼21,000 data points, 2007–2017) were combined from across North America ranging in yield from 1,000– 7,500 kg ha−1. Cluster analysis was used to stratify each individual field study into similar environmental (soil × climate) clusters and into high (HYL), medium (MYL), and low (LYL) yield levels. Agronomically optimal seeding rates (AOSR) were calculated and Monte Carlo risk analysis was implemented. Within the two northern most clusters the AOSR was higher in the LYL followed by the MYL and then HYL. Within the farthest south cluster, a relatively small (±15,000 seeds ha−1) change in seeding rate from the MYL was required to reach the AOSR of the LYL and HYL, respectively. The increase in seeding rate to reach the LYL AOSR was relatively greater (5x) than the decrease to reach the HYL AOSR within the northern most cluster. Regardless, seeding rates below the AOSR presented substantial risk and potential yield loss, while seeding rates above provided slight risk reduction and yield increases. Specific to LYLs and MYLs, establishing and maintaining an adequate plant stand until harvest maximized yield regardless of the seeding rate, while maximizing seed number was important with lower seeding rates. These findings will help growers manage their soybean seed investment by adjusting seeding rates based upon the productivity of the environment.Fil: Gaspar, Adam P.. Dow Agrosciences Argentina Sociedad de Responsabilidad Limitada.; ArgentinaFil: Mourtzinis, Spyridon. University of Wisconsin; Estados UnidosFil: Kyle, Don. Dow Agrosciences Argentina Sociedad de Responsabilidad Limitada.; ArgentinaFil: Galdi, Eric. Dow Agrosciences Argentina Sociedad de Responsabilidad Limitada.; ArgentinaFil: Lindsey, Laura E.. Ohio State University; Estados UnidosFil: Hamman, William P.. Ohio State University; Estados UnidosFil: Matcham, Emma G. University of Wisconsin; Estados UnidosFil: Kandel, Hans J.. North Dakota State University; Estados UnidosFil: Schmitz, Peder. North Dakota State University; Estados UnidosFil: Stanley, Jordan D.. North Dakota State University; Estados UnidosFil: Schmidt, John P.. Dow Agrosciences Argentina Sociedad de Responsabilidad Limitada.; ArgentinaFil: Mueller, Daren S.. University of Iowa; Estados UnidosFil: Nafziger, Emerson D.. University of Illinois; Estados UnidosFil: Ross, Jeremy. University of Arkansas for Medical Sciences; Estados UnidosFil: Carter, Paul R.. Dow Agrosciences Argentina Sociedad de Responsabilidad Limitada.; ArgentinaFil: Varenhorst, Adam J.. University of South Dakota; Estados UnidosFil: Wise, Kiersten A.. University of Kentucky; Estados UnidosFil: Ciampitti, Ignacio Antonio. Kansas State University; Estados UnidosFil: Carciochi, Walter Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Kansas State University; Estados UnidosFil: Chilvers, Martin I.. Michigan State University; Estados UnidosFil: Hauswedell, Brady. University of South Dakota; Estados UnidosFil: Tenuta, Albert U.. University of Guelph; CanadáFil: Conley, Shawn P.. University of Wisconsin; Estados Unido

The Dynamics of Plant Cell-Wall Polysaccharide Decomposition in Leaf-Cutting Ant Fungus Gardens

The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants

Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

Differences in Perceptions of Incivility Among Disciplines in Higher Education

Background: Incivility occurs in various forms in higher education and negatively affects teaching and learning outcomes. It has not been determined if incivility is more prevalent in one discipline than another. Purpose: The purpose of this study was to compare faculty and student perceptions of incivility across disciplines at a large public university. Methods: In this descriptive comparative study, a convenience sample of 156 faculty and 421 students completed the Incivility in Higher Education–Revised survey electronically. Results: The total sample was 577. Nursing reported the highest level of perceived incivility, with all other disciplines also reporting some level of incivility. Faculty perceived more incivility than students. Conclusions:With a national awareness of incivility in nursing education, this study shows that incivility also exists in other disciplines and is a starting point for addressing its impact on higher education

Learning and Retention Using Virtual Reality in a Decontamination Simulation

AIM The purpose of this study was to examine the longitudinal effects of virtual reality simulation (VRS) on learning outcomes and retention. BACKGROUND Disaster preparation for health care professionals is seriously inadequate. VRS offers an opportunity to practice within a realistic and safe environment, but little is known about learning and retention using this pedagogy. METHOD A quasiexperimental design was used to examine the use of VRS with baccalaureate nursing students in two different nursing programs in terms of the skill of decontamination. RESULTS Results indicate that VRS is at least as good as traditional methods and is superior in some cases for retention of knowledge and performance of skills. CONCLUSION VRS may provide a valuable option for promoting skill development and retention. More research is needed to determine how to prepare nurses for skills that may not be required until months or even years after initial introduction