Dynamic modeling and analysis of an automatic reconfigurable shipboard power system

In future United States Naval warships, all ship power will be converted to electricity and distributed to a complex system of loads through transmission lines. Because these loads are dynamic by nature, it is necessary to develop a control system that can both respond to these changes and rapidly alter the power system interconnections for protection and efficiency. This thesis describes the development of models and analysis methods for evaluating a centralized method of shipboard reconfiguration control. This control utilizes sub-cycle, time-based measurements used to estimate equivalent impedances that characterize the dynamic power system. An optimization algorithm determines steady state switch configurations and a logic routine checks the validity of intermediate switch states. Several test cases are simulated to demonstrate emergency and non-emergency reconfiguration. The speed and accuracy of reconfiguration are dependent on three conditions: current and voltage noise level, the algorithm used to determine equivalent impedances, and the dynamic nature of the load change. With adequate computing resources, careful selection of filter parameters, i.e., the cessation of a transient, and minimal noise, reconfiguration within one cycle is possible.Mechanical Engineerin

The Effects of Removal of Juniperus virginiana L. Trees and Litter from a Central Oklahoma Grassland

We studied species composition after Juniperus virginiana tree and litter removal in a central Oklahoma grassland. Tree removal had the most significant effect on stems per quadrat and vegetation cover. Litter removal effects were not as strong. However, stems per quadrat and vegetation cover in litter removal treatments were higher than in litter intact treatments. Species richness increased for all treatments in the first year post-treatment, after which species richness declined at every sampling period and in every treatment for the duration of the study. Absolute cover of typical prairie species increased in the cut with no litter treatment hereas cover of woody forest species increased in the no cut with no litter treatment. We suggest that even without prescribed fire, redcedar tree removal may result in a return of prairie vegetation. However, additional efforts besides tree removal may be required to restore some invaded grasslands

Measuring revealing: An instrument for non-pecuniary outbound open innovation

Open innovation (OI) refers to the in- and out-bound flows of knowledge for financial gain or non-pecuniary reasons. Investigation into pecuniary and especially inbound innovation types has advanced rapidly and the relationships between these types of OI, organizational factors and innovation performance are now well understood. Non-pecuniary outbound OI has received less attention, perhaps because it is contrary to the expectation of capturing rents from innovation. Yet, knowledge sharing is critical to innovation and future value capture because it improves organizational learning through interaction with the external environment. In this paper we address this gap by following a four-step process to propose and validate a reliable scale of non-pecuniary outbound OI (revealing). Our findings indicate that revealing is reflected by five factors, namely complementary capabilities, diffusion, generosity, enhancement, and co-creation with other firms. We conclude by discussing how this scale can be used to advance studies of OI

Can the use of femoral notch view alone decrease measurement error of distal interlocking screws after retrograde femoral nailing

OBJECTIVES: Determine if using different fluoroscopic views of the knee (Notch or Tangential) improves accuracy of screw lengths assessment compared to the standard posteroanterior (PA). PARTICIPANTS AND METHODS: Orthopaedic surgeons at three ACGME-accredited residency programs were asked via survey to assess screw lengths on PA, femoral notch, and tangential radiographic views. RESULTS: Responders correctly identified screw length using PA, femoral notch, and medial tangential views at rates of 46.75%, 52.27%, and 44.37% respectively. Respondents detected overall screw length discrepancies most accurately using the femoral notch view (Odds Ratio 1.26; 95% confidence interval: 1.07-1.47; P \u3c 0.005). There was no statistical difference between the residents and faculty cohort in ability to detect screw length discrepancy. CONCLUSION: Differentiating distal interlocking screw lengths on traditional imaging (AP/Notch/Tangential) is poor. The femoral notch view significantly improves accuracy in radiographic determination of screw length. The femoral notch view should be used in conjunction with the traditional PA view to maximize sensitivity and specificity for detecting prominent screws

Negative Allosteric Modulators That Target Human α4β2 Neuronal Nicotinic Receptors

Allosteric modulation of neuronal nicotinic acetylcholine receptors (nAChRs) is considered to be one of the most promising approaches for therapeutics. We have previously reported on the pharmacological activity of several compounds that act as negative allosteric modulators (NAMs) of nAChRs. In the following studies, the effects of 30 NAMs from our small chemical library on both human α4β2 (Hα4β2) and human α3β4 (Hα3β4) nAChRs expressed in human embryonic kidney ts201 cells were investigated. During calcium accumulation assays, these NAMs inhibited nAChR activation with IC50 values ranging from 2.4 μM to more than 100 μM. Several NAMs showed relative selectivity for Hα4β2 nAChRs with IC50 values in the low micromolar range. A lead molecule, KAB-18, was identified that shows relative selectivity for Hα4β2 nAChRs. This molecule contains three phenyl rings, one piperidine ring, and one ester bond linkage. Structure–activity relationship (SAR) analyses of our data revealed three regions of KAB-18 that contribute to its relative selectivity. Predictive three-dimensional quantitative SAR (comparative molecular field analysis and comparative molecular similarity indices analysis) models were generated from these data, and a pharmacophore model was constructed to determine the chemical features that are important for biological activity. Using docking approaches and molecular dynamics on a Hα4β2 nAChR homology model, a binding mode for KAB-18 at the α/β subunit interface that corresponds to the predicted pharmacophore is described. This binding mode was supported by mutagenesis studies. In summary, these studies highlight the importance of SAR, computational, and molecular biology approaches for the design and synthesis of potent and selective antagonists targeting specific nAChR subtypes

#InSituPathologists: how the #USCAP2015 meeting went viral on Twitter and founded the social media movement for the United States and Canadian Academy of Pathology

Professional medical conferences over the past five years have seen an enormous increase in the use of Twitter in real-time, also known as live-tweeting . At the United States and Canadian Academy of Pathology (USCAP) 2015 annual meeting, 24 attendees (the authors) volunteered to participate in a live-tweet group, the #InSituPathologists. This group, along with other attendees, kept the world updated via Twitter about the happenings at the annual meeting. There were 6,524 #USCAP2015 tweets made by 662 individual Twitter users; these generated 5,869,323 unique impressions (potential tweet-views) over a 13-day time span encompassing the dates of the annual meeting. Herein we document the successful implementation of the first official USCAP annual meeting live-tweet group, including the pros/cons of live-tweeting and other experiences of the original #InSituPathologists group members. No prior peer-reviewed publications to our knowledge have described in depth the use of an organized group to live-tweet a pathology meeting. We believe our group to be the first of its kind in the field of pathology