Optimal Capital Structure in Centralized Agricultural Cooperatives

Agribusiness,

Optimal control of two qubits via a single cavity drive in circuit quantum electrodynamics

Optimization of the fidelity of control operations is of critical importance in the pursuit of fault-tolerant quantum computation. We apply optimal control techniques to demonstrate that a single drive via the cavity in circuit quantum electrodynamics can implement a high-fidelity two-qubit all-microwave gate that directly entangles the qubits via the mutual qubit-cavity couplings. This is performed by driving at one of the qubits' frequencies which generates a conditional two-qubit gate, but will also generate other spurious interactions. These optimal control techniques are used to find pulse shapes that can perform this two-qubit gate with high fidelity, robust against errors in the system parameters. The simulations were all performed using experimentally relevant parameters and constraints.Comment: Final published versio

The revolving door: A closer look at major factors in volunteers’ intention to quit

In nonprofit organizations, volunteer coordinators deal with high rates of volunteer turnover due, in part, to increased levels of volunteer burnout. This study sought to identify how burnout can help explain volunteers’ intention to quit and identify two potential antecedents of burnout: voice and role ambiguity. Specifically, it is hypothesized that volunteer voice and role ambiguity affects volunteers’ intention to quit through their relationship with volunteer burnout. Data were obtained from volunteers working in an animal welfare organization in the western United States (N = 151). An online survey was administered to volunteers who responded to a variety of questions and scales concerning their experiences as volunteers in an animal welfare organization. Structural equation modeling was used to test the mediation hypotheses. The findings provide tentative support that volunteer burnout mediates the relationship between two potential predictors of burnout (e.g., perception of voice and role ambiguity) and intention to quit. Consistent with conservation of resources theory, volunteers who are drained of their cognitive resources through dealing with a lack of voice and ambiguous volunteer role situations experience increased burnout. The practical and theoretical significance of these findings are discussed

The relationship between reproduction and mortality in triploid Crassostrea virginica: a matter of economic importance

The goal of this project is to maximize survival for commercially produced triploid Crassostrea virginica oysters in Virginia. Over the last few years, commercial oyster growers in Virginia have reported significant mortality events of triploid oysters during the spring and summer months. The summer of 2014 was the worst yet, as growers across the state reported summer mortality, most severe on the Eastern shore and in some cases as high as 85% of the crop (Karen Hudson, personal communication). Surviving oysters from some of these mortality events were sent to the Virginia Institute of Marine Science and several of the triploid oysters examined had significant gonadal development, an unexpected finding considering previous experience with triploid C. virginica suggests they are typically sterile. Genetics may be an explanation for the unusually high reproductive effort and mortality rate, as further investigation revealed much of the seed grown in Virginia is produced by crossing Virginia tetraploids with Maine diploids. The specific objectives are to determine variability in gametogenesis of triploids owing to crosses from different geographic origins and to establish the relationship between this variation and mortality. In February of 2015, two tetraploid broodstocks from Virginia (V) and Louisiana (L) origins were crossed with two diploid brood stocks of Virginia (V) and Maine (M) origin to create four triploid constructs (VVV, VVM, LLV, LLM). Diploid VV, VM, MV, and MM constructs were produced as controls. Seed was deployed to three commercial sites on the Eastern Shore that have experienced severe triploid mortality, as well as to a site on the Rappahannock River and a site on the York River. Oysters will be sampled monthly during the spring and summer months of 2016. Sampling will consist of monitoring growth and survival, as well as assessing the condition, gametogenic characteristics, and reproductive effort of triploids and diploids from each culture at each commercial site. Histology will be the primary tool for assessing the gametogenic characteristics and reproductive effort of sampled oysters

Extra-anatomic arterial reconstruction with ligation of common iliac arteries and embolization of the aneurysm for the treatment of abdominal aortic aneurysms in high-risk patients

AbstractPurpose: The mortality of an unrepaired abdominal aortic aneurysm (AAA) generally exceeds the mortality associated with surgical repair. However, as our longevity increases, more frequently we see patients whose risk of surgical repair approximates the risk of rupture. We present an extra-anatomic bypass graft with complete aneurysm exclusion by iliac ligation and coil embolization of the aneurysm as an alternative for these high-risk patients. Methods: An extra-anatomic bypass graft, followed by bilateral iliac artery ligation (retroperitoneal approach) and complete coil embolization of the AAA, was performed in eight patients (mean age, 77 years) found to be at prohibitive operative risk because of multiple comorbidities (American Society of Anesthesiologists class IV). Most patients (5 of 8) were symptomatic on presentation with a mean AAA diameter of 7 cm (range, 6.7-9.5 cm). We repair approximately 30 infrarenal aneurysms per year electively at our institution. Results: All patients tolerated the surgical procedures. The average hospital stay was 8 days. All but two aneurysms demonstrated complete thrombosis by 48 hours. After 48 months there was no incidence of graft thrombosis, peripheral ischemia, visceral ischemia or thrombus infection. There was one perioperative death from aspiration pneumonia. Seventy-five percent (6 of 8) of patients have survived at least 1 year without surgical complications. No patient has had a ruptured aneurysm. Conclusion: Combining an extra-anatomic bypass graft and complete exclusion of the AAA by ligation of the common iliac arteries and a coil embolization is an effective, less invasive treatment option for patients with AAA and prohibitive operative risk. We emphasize the need for complete embolization documented by decreased aneurysm size. (J Vasc Surg 2001;33:745-51.

Do We Really Need Another Meeting? The Science of Workplace Meetings

Meetings are routine in organizations, but their value is often questioned by the employees who must sit through them daily. The science of meetings that has emerged as of late provides necessary direction toward improving meetings, but an evaluation of the current state of the science is much needed. In this review, we examine current directions for the psychological science of workplace meetings, with a focus on applying scientific findings about the activities that occur before, during, and after meetings that facilitate success. We conclude with concrete recommendations and a checklist for promoting good meetings, as well as some thoughts on the future of the science of workplace meetings