A Capstone Project on Robust Dynamic Positioning and Data Acquisition Systems

The United States Coast Guard is responsible for enforcing Dynamic Positioning System (DPS) standards in the maritime industry. It is important for the members of the U. S. Coast Guard to understand how these systems work. Students have gained a much greater understanding of how DPS platforms work and what might be required to maintain them by building one from scratch. Aside from this, the project has served as a great opportunity to work on a one year term project that may resemble engineering or acquisitions projects that might be encountered in the students’ future careers. The overall goal of the Robust Dynamic Positioning and Data Acquisition System project was to prototype a dynamic positioning system similar to the ones on buoy tenders in the fleet. The primary goal was to maintain a desired heading and position within a certain range. The secondary goals included robust capabilities (the ability to continue functioning despite motor failures) and data acquisition (to analyze system performance post-testing). Students built a vessel from scratch out of a salvage drum and an inner tube for buoyancy. The internal construction consists of three tiers containing batteries at the lowest level, an onboard computer at the second level, and control hardware at the top level (micro controllers, H-bridges, and fuse boxes). Students successfully used a light detection and ranging (LIDAR) device to determine the relative position to two stationary poles. They were able to communicate with the onboard computer via either a wired connection or a remote desktop connection through an ad-hoc wireless network. All programming for this project was done in MATLAB®. Students have completed all project milestones through the application of past courses they have taken in computer control systems, network communication, and digital signal processing at the U.S. Coast Guard Academy. The first challenge of this project was to focus on constructing the vessel and installing the control hardware. One of the obstacles for the students was establishing communication between the various pieces of software, hardware, and the power distribution system. The LIDAR sensor determined the vessel’s relative position and heading to two stationary poles. Using the position and heading resolution algorithms, students conducted a set of system identification tests in an indoor tank to determine how the system reacts to various thrusts from the motors. This allowed students to collect “Open-Loop” system data. Using the data acquisition system, students were able to identify the system and calculate coefficients for the controller and implement a “Closed- Loop” control system. Students successfully implemented a proportional integral derivative (PID) controller that satisfies all design requirements including robust functionality. Currently, all milestones for the project have been accomplished and plans for continuation of the project are underway

The efficiency and effectiveness of utilizing diagrams in interviews: an assessment of participatory diagramming and graphic elicitation

Abstract Background This paper focuses on measuring the efficiency and effectiveness of two diagramming methods employed in key informant interviews with clinicians and health care administrators. The two methods are 'participatory diagramming', where the respondent creates a diagram that assists in their communication of answers, and 'graphic elicitation', where a researcher-prepared diagram is used to stimulate data collection. Methods These two diagramming methods were applied in key informant interviews and their value in efficiently and effectively gathering data was assessed based on quantitative measures and qualitative observations. Results Assessment of the two diagramming methods suggests that participatory diagramming is an efficient method for collecting data in graphic form, but may not generate the depth of verbal response that many qualitative researchers seek. In contrast, graphic elicitation was more intuitive, better understood and preferred by most respondents, and often provided more contemplative verbal responses, however this was achieved at the expense of more interview time. Conclusion Diagramming methods are important for eliciting interview data that are often difficult to obtain through traditional verbal exchanges. Subject to the methodological limitations of the study, our findings suggest that while participatory diagramming and graphic elicitation have specific strengths and weaknesses, their combined use can provide complementary information that would not likely occur with the application of only one diagramming method. The methodological insights gained by examining the efficiency and effectiveness of these diagramming methods in our study should be helpful to other researchers considering their incorporation into qualitative research designs

Natural Killer Cell Signal Integration Balances Synapse Symmetry and Migration

Imaging immune surveillance by natural killer (NK) cells has revealed that integration of activating and inhibitory signals determines whether or not NK cells stop to kill the target cell or retain a migratory configuration

Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function

Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Understanding the social context of fatal road traffic collisions among young people: A qualitative analysis of narrative text in coroners' records

Background: Deaths and injuries on the road remain a major cause of premature death among young people across the world. Routinely collected data usually focuses on the mechanism of road traffic collisions and basic demographic data of those involved. This study aimed to supplement these routine sources with a thematic analysis of narrative text contained in coroners' records, to explore the wider social context in which collisions occur. Methods. Thematic analysis of narrative text from Coroners' records, retrieved from thirty-four fatalities among young people (16-24 year olds) occurring as a result of thirty road traffic collisions in a rural county in the south of England over the period 2005-2010. Results: Six key themes emerged: social driving, driving experience, interest in motor vehicles, driving behaviour, perception of driving ability, and emotional distress. Social driving (defined as a group of related behaviours including: driving as a social event in itself (i.e. without a pre-specified destination); driving to or from a social event; driving with accompanying passengers; driving late at night; driving where alcohol or drugs were a feature of the journey) was identified as a common feature across cases. Conclusions: Analysis of the wider social context in which road traffic collisions occur in young people can provide important information for understanding why collisions happen and developing targeted interventions to prevent them. It can complement routinely collected data, which often focuses on events immediately preceding a collision. Qualitative analysis of narrative text in coroner's records may provide a way of providing this type of information. These findings provide additional support for the case for Graduated Driver Licensing programmes to reduce collisions involving young people, and also suggest that road safety interventions need to take a more community development approach, recognising the importance of social context and focusing on social networks of young people. © 2014 Pilkington et al.; licensee BioMed Central Ltd

An Innovative Approach to Teaching An Undergraduate Electromagnetics, Antennas and Propagation Course

Abstract -In this paper an innovative approach is taken to teach electromagnetics (EM), antenna theory and signal propagation to undergraduate students. The method relies on hardware design and implementation projects that reinforce the underlying theory, enable the student to gain practical insight into the various EM topics, and ultimately provide the student with a working knowledge to analyze, problem solve and engineer EM systems. Topics include the basic EM theory, electromagnetic compatibility (EMC) and interference (EMI), transmission lines, antennas, phased arrays, and wireless propagation. Projects range the prosaic EM experiments to more open ended design with multiple possible solutions

CHARACTERIZING HOST-PATHOGEN INTERACTIONS IN THE HEART IN A MOUSE MODEL OF AFRICAN TRYPANOSOMIASIS

Trypanosoma brucei is a parasite which represents a threat to human and animal health throughout sub-Saharan Africa. Although T. brucei colonizes extravascular spaces, where it causes organ damage and inflammation, host-pathogen interactions in these spaces and their consequences remain poorly understood. There is evidence that T. brucei colonizes the heart, causing inflammation and cardiac dysfunction. However, despite evidence that the heart is an important focus of pathology in Human African Trypanosomiasis (HAT), the understanding of host-pathogen interactions in the heart during T. brucei infection remains to be thoroughly investigated. To investigate the host-pathogen interactions in the heart during T. brucei infection, we developed a mouse model of HAT. We demonstrate that in this model, T. brucei invades and colonizes the heart within a week of infection, resulting in myocarditis and cardiac dysfunction which is similar to that exhibited in natural infection. Using this model, we further investigated host-pathogen interactions in the heart. On the host side, we find that T. brucei infection causes an intracardiac immune response characterized by increased numbers of most cell types—most notably including CD8+ T cells, Natural Killer cells, and pro-inflammatory macrophages, indicating an immunopathological component of the cardiac damage seen in T. brucei infection. On the parasite side, we find that intracardiac parasites exhibit a unique transcriptome at both early and late infection timepoints, suggesting that they represent a unique population compared to intravascular parasites. In particular, intracardiac parasites are more proliferative and upregulate fewer stress-response genes than intravascular parasites, suggesting that the heart is a relatively protected parasite reservoir. This is in agreement with our findings on the host side, which indicate a relatively ineffective intracardiac immune response. In our transcriptomic data, we identified two trypanosomal genes which we hypothesized were involved in cardiac colonization by T. brucei. On further investigation of these genes, we find that they are more generally involved in T. brucei pathogenesis. Knockout of these genes results in a decrease in T. brucei virulence, with mice exhibiting longer survival times and a less severe clinical phenotype. However, their function and specific contributions to pathogenesis remain to be fully characterized